PARENT SESSION
5C Ecological relevance of endocrine disruption
9:00 AM to 7:00 PM, Tuesday, 08 May 2001
Session Chair:

(T/FF213) Effects of 17 -ethinylestradiol on the reproduction of Ceriodaphnia reticulata and Sida crystallina.

Jaser, Wolfgang¹, Severin, Gabriele¹, Juetting, Uta², Juettner, Ingrid¹, Schramm, Karl-Werner¹, Kettrup, Antonius¹, ^{1 2}

ABSTRACT- Single-species-tests allow the assessment of chronical effects of endocrine disruptors on organisms under laboratory conditions. In the current study 3-generation-tests with Ceriodaphnia reticulata and Sida crystallina were carried out to examine the influence of the synthetic hormone 17-ethinylestradiol (EE) on the reproduction of these cladoceran species. For each species, six different concentrations (10-500 g/L EE) and two controls were tested with eight replicates for a duration of four weeks. The test was initiated by transferring one neonate individual into a test vessel which was incubated under standardized conditions (52-56% humidity, 16h light (25°C), 8h (22°C) darkness). Every two days, the medium was renewed and life history parameters such as survivorship of the adults and juveniles, clutch size, first appearance and number of produced offspring were investigated. The ANOVA method as well as Kaplan-Meier analyses of survivorship were applied. The juvenile phase of Sida was significantly shorter at concentrations above 100 g/L EE. For Ceriodaphnia, 17-ethinylestradiol generally caused a higher mortality of the newly hatched juveniles. Additionally conducted acute toxicity tests showed that Ceriodaphnia reticulata was more sensitive towards the substance compared to Sida crystallina.

Key words: zooplankton, ethinylestradiol, chronic toxicity, reproduction